1. Field of the Invention
The present invention relates to a drawing apparatus for performing drawing on a substrate with a plurality of charged particle beams, and a method of manufacturing an article.
2. Description of the Related Art
As a drawing apparatus used to manufacture a device such as a semiconductor integrate circuit, Japanese Patent Laid-Open No. 62-144323 proposes a drawing apparatus that performs drawing simultaneously on a plurality of shot regions of a substrate using a plurality of electron optical systems (charged particle optical systems) to increase the productivity. When simultaneously performing drawing using a plurality of electron optical systems, the total quantity of drawing pattern data held and handled by the electron optical systems increases in accordance with the number of electron optical systems. In many cases, however, patterns having the same shape are drawn on the plurality of shot regions.
In the drawing apparatus described in Japanese Patent Laid-Open No. 62-144323, drawing data used by the plurality of electron optical systems are shared by the plurality of shot regions. The drawing is performed simultaneously on the plurality of shot regions using the same drawing data, thereby reducing the scale of drawing data to be held and handled. Additionally, in the drawing apparatus described in Japanese Patent Laid-Open No. 62-144323, a plurality of electron optical systems each including an independent correction device are periodically arranged. When performing overlay drawing on an already drawn underlayer pattern, the position of the drawing pattern to be overlaid is corrected for each electron optical system based on the shape of the underlayer pattern.
FIG. 1 shows a state in which drawing is performed simultaneously on a plurality of shot regions of a wafer using a plurality of such electron optical systems. In FIG. 1, drawing is performed on 5 (rows)×5 (columns)=25 shot regions on a wafer 10 using three electron optical systems. Each of three electron optical systems Col_1, Col_2, and Col_3 can project a plurality of or 5 (rows)×5 (columns) electron beams to the wafer 10.
When the wafer 10 is moved to the upper side of FIG. 1 with respect to the electron optical systems Col_1, Col_2, and Col_3 by a stage (not shown) on which the wafer 10 is placed, the electron optical systems Col_1 to Col_3 draw stripe regions S1 to S3, respectively. In this stripe drawing, multiple drawing is performed on the wafer 10 by the plurality of electron beams of the electron optical systems which are arrayed in the moving direction of the wafer 10 (column direction). The irradiating doses of the electron beams on the wafer 10 are controlled by on/off-controlling irradiation of the electron beams.
The irradiating doses of the electron beams are controlled repetitively using drawing data generated from design data in advance. Drawing data necessary for the electron optical systems Col_1 to Col_3 to simultaneously perform drawing is drawing data for the widths of the stripe regions S1 to S3. Since the drawing position changes between the shot regions, as shown in FIG. 1, the drawing data changes between the electron optical systems. It is therefore necessary to redundantly generate drawing data that changes between the electron optical systems in advance and hold the data, resulting in an increase in the total quantity of drawing data.
To solve this problem, Japanese Patent No. 4308504 describes electron beam drawing capable of mechanically adjusting the distances between the optical axes of a plurality of electron optical systems.
However, the method described in Japanese Patent No. 4308504 which mechanically adjusts the distances between the optical axes of electron optical systems to shared drawing data by the electron optical systems has a problem of mechanical adjustment precision and drawing precision.